The objective of this physiological study is to compare two preoxygenation techniques (non-invasive ventilation combined with high-flow nasal oxygen versus non-invasive ventilation alone) by monitoring end-tidal oxygen fraction (FeO₂) and the Oxygen Reserve Index (ORI) during 3 minutes of preoxygenation in healthy volunteers.
An intubation procedure is performed in several successive phases: 1. Preoxygenation phase: This phase consists of administering 100% oxygen for 3 to 5 minutes in order to increase oxygen reserves. 2. Alveolar hypoventilation phase: This phase begins with the administration of anesthetic agents, leading to a reduction in spontaneous ventilation. 3. Apnea phase: During this phase, laryngoscopy is performed and the endotracheal tube is inserted into the trachea. 4. Initiation of invasive mechanical ventilation: Once intubation is successful, the patient is placed on assisted mechanical ventilation. Several devices can be used to perform preoxygenation: * Bag-valve mask (BVM) * High-flow nasal cannula therapy (HFNC) * Non-invasive ventilation (NIV): Current recommendations from critical care societies suggest the use of: * BVM or HFNC for non-hypoxemic patients * NIV for hypoxemic patients A single-center randomized controlled study (OPTINIV) demonstrated the benefit of combining NIV and HFNC for preoxygenation. However, placing an NIV mask over HFNC nasal cannulae may result in mask leaks, leading to ambient air entrainment, as well as a potential risk of excessive airway pressure related to HFNC. In this study, HFNC cannulae in the control group were left in place but inactive. Consequently, it remains difficult to determine whether the observed efficacy of the NIV + HFNC combination was related to leak compensation by HFNC during preoxygenation, or to apneic oxygenation provided by HFNC between laryngoscopy and successful intubation.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
NONE
Enrollment
30
Each preoxygenation session will last 3 minutes with the participant positioned at a 30° head-up angle. A washout period of 10 minutes will be applied between each preoxygenation session, and initiation of the second preoxygenation technique will require the Oxygen Reserve Index (ORI) to return to 0. Monitoring will include: * Oxygen Reserve Index (ORI) * End-tidal oxygen fraction (FeO₂) measured at the NIV mask * Peripheral oxygen saturation (SpO₂)
Each preoxygenation session will last 3 minutes with the participant positioned at a 30° head-up angle. A washout period of 10 minutes will be applied between each preoxygenation session, and initiation of the second preoxygenation technique will require the Oxygen Reserve Index (ORI) to return to 0. Monitoring will include: * Oxygen Reserve Index (ORI) * End-tidal oxygen fraction (FeO₂) measured at the NIV mask * Peripheral oxygen saturation (SpO₂)
CHU Orléans
Orléans, France
Change in end-tidal oxygen fraction (FeO2) at the end of each preoxygenation technique
FeO2 will be collected every 12 seconds during preoxygenation. The mean FeO2 value at 3 minutes will be used for comparison between techniques.
Time frame: 3 minutes
Change in end-tidal oxygen fraction (FeO2) during each preoxygenation technique
Change in end-tidal oxygen fraction (FeO₂) will be evaluated by recording FeO₂ every 12 seconds during the 3-minute preoxygenation period.
Time frame: 3 minutes
Maximum FeO2 value
Maximum FeO2 value achieved during the 3 minutes of each preoxygenation technique
Time frame: 3 minutes
Average Oxygen Reserve Index (ORI) value
The ORI will be recorded every 30 seconds during preoxygenation. The mean ORI value at 3 minutes will be used for comparison.
Time frame: 3 minutes
Maximum ORI value
Maximum ORI value achieved during the 3 minutes of each preoxygenation technique
Time frame: 3 minutes
Change in ORI during each preoxygenation technique
Change in ORI will be evaluated by recording ORI every 2 seconds during the 3 minutes of preoxygenation.
Time frame: 3 minutes
Time (in seconds) required to reach an ORI value ≥ 0.60 and FeO2 ≥ 90% during the 3 minutes of each preoxygenation technique
Time frame: 3 minutes
Time (in seconds) for ORI to return to 0 after cessation of preoxygenation.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Time frame: 3 minutes
Change in peripheral oxygen saturation (SpO2) during each preoxygenation technique
The change in SpO2 will be evaluated by recording SpO2 every 12 seconds during the 3 minutes of preoxygenation.
Time frame: 3 minutes
Change in ventilator parameters (inspiratory and expiratory tidal volumes)
Change in inspiratory and expiratory tidal volumes measured every 30 seconds during the 3 minutes of preoxygenation.
Time frame: 3 minutes